This is a Continuation of International Application No. PCT/EP01/01270, filed Feb. 6, 2001 which in turn claims priority of German application DE 100 06 409.4, filed Feb. 14, 2000, the priority of both of which are claimed under 35 U.S.C. xc2xa7xc2xa7119 and 120. International Application PCT/EP01/01270 was published in German, but not in English, as WO 01/59365 A1 on Aug. 16, 2001.
1. Field of the Invention
The present invention relates to a new luminaire for controlling the distribution of lights.
2. Description of the Related Art
Such a luminaire is described for example in DE 44 43 916 A1. There, below an elongate lamp, is first arranged a raster reflector consisting of side reflectors and transverse lamellae, with the aid of which the greater proportion of the light emitted by the lamp is directed and radiated downwardly without dazzle effect. The employment of such a raster reflector is of advantage for example in offices having a series of computer-screen work stations, since the light is to a certain degree freed from transverse dazzle and thus reflections on the screens can be avoided.
The luminaire described in the above-mentioned document further has an outer reflector onto which falls the light radiated from the lamp to the sides or upwardly. In this manner the region surrounding the lamp is additionally brightened, which on the one hand makes it possible easily to recognize whether the luminaire is switched on or not, but on the other hand it is also perceived by an observer as substantially more pleasant than the light of a pure raster luminaire, with which the entire light is radiated solely downwardly. Thereby, the outer reflector may have a diffusely reflecting surface, in order to attain a brightening of the region surrounding the lamp which is as uniform as possible. A further possibility consists however also in mounting below the outer reflector additionally a translucent (opalescent) plate.
It is an object of the present invention to improve such a luminaire in that with the luminaire new and optically appealing illumination effects can be attained.
The luminaire in accordance with the invention comprises a lamp and at least one concavely curved reflector arranged, as seen in a radiation direction of the lamp, behind or to the side behind the lamp. In accordance with the invention, color filters are so arranged to a side of the lamp that only the light which is radiated onto the concavely curved reflector is changed in its color composition, whereas in contrast light which is radiated from the lamp in the radiation direction is not influenced in its color composition by the filters.
Through this, the region surrounding the lamp appears in a different color, so that through the choice of a suitable filter various effects and moods can be created. For example, a substantially more pleasant atmosphere can be created in that the light directed onto the concave reflector is given a warmer color tone with the aid of the color filter for example colored slightly yellow or orange. In contrast, a more blue light is perceived, rather, as colder, for which reason it would suggest itself to employ a blue colored color filter in warmer regions. Since for the achievement of such illumination effects the concavely curved reflector need not itself be colored but can as usual be white, in the switched-off condition the region surrounding the lamp appears, as before, colorless or white, the above-described effects appear only in the switched-on condition of the lamp.
The alteration of the color composition of light by means of appropriate filters is already known from DE 39 08 148 A1 or DE 446 406. However, with the luminaire known from DE 39 08 148 A1 the entire light emitted by the lamp is to be changed in color. In DE 446 406 the light beams emitted in a certain direction encounter color filters, whereby a particular region of the room appears in a different color. In contrast, with the luminaire of the present invention, only the reflector arranged behind or to the side behind the lamp is to appear in another color, whereas in contrast the light proportion radiated in the radiation direction and employed for actual illumination remains unaltered in terms of color.
Further developments of the invention are described and claimed herein.
Since the color appearance of the concave reflector is brought about only by means of the color filter in accordance with the invention, the lamp can again be configured more flexibly in that the color filter can be altered in its effect. For example, there can be provided a mechanism which increases or reduces the filter effect of the color filter. With a lamp which is elongated along an axis, this can be effected for example in that the filter is rotatable around an axis running parallel to the lamp. The filter effect then depends upon the angle included between the color filter and the incident light in each case.
In a further development of the invention, there is provided a special configuration of the filter. By means of the side mounting of white transverse webs, the direct viewing of the filter element is prevented, so that upon observation of the overall luminaire only the concave reflector appears colored.
Preferably there is arranged before the lamp additionally a light distributor element, e.g. a raster, grid, perforated sheet or the like. Since the light emitted via this light distributor element remains unchanged in its color the luminaire in accordance with the invention again fulfils its main object, namely an effective illumination of the surrounding room.
With luminaires of this kind it is as a rule desired that the concavely curved reflector has a uniform light density over its entire width. In a further development of the invention various measures can thus be taken in order to attain a uniform light density. Normally, for this purpose the concave reflector has a curvature calculated in advance from theory, which however has the consequence that the reflector is then relatively high. In order then to configure the luminaire to be more flat in its entirety, it can be provided that a partially light permeable diffusor is arranged before the concave reflector, which diffusor to a certain degree brings about an equalization of the light density over the width of the reflector. This equalization can further also be supported in that the reflective capability of the reflector is different over its width, whereby the reflector has in its regions distant from the lamp a greater reflective capability than in the regions closer to the lamp. Further, there may be arranged to the side of the lamp further diffusers, or the color filter may be formed itself to be diffusely light permeable.
A further illumination effect can be attained in that the concave reflector is itself partially light permeable. If the luminaire is for example a surface-mounted luminaire or a hanging luminaire, the ceiling region above the luminaire is additionally brightened. This also then appears in a color tone corresponding to the color filter. In contrast thereto, it can also be provided that although the concave reflector is partially light permeable, there is however arranged above this reflector at least one further lamp. This may in turn likewise be surrounded by a color filter, so that a plurality of different illumination effects can be attained with different color tones.
Along with the two above-mentioned examples of a ceiling surface-mounted luminaire or a hanging luminaire, the luminaire in accordance with the invention can be configured also as a recess luminaire or in other forms.